Shortening a 9 in. at home...ideas...D.Hearne,old time hot rodders?

[10secgoal]

That's right. At home. Too damn cheap to pay for it. I understand how critical this is but I have an idea I think will work and wanted some more ideas that may help.This kid of mine has put a hurtin' on the hobby.WELL worth it though.
Anyway...here's my idea. I want to cut the tube an measure the ID of the tube and sleeve the the inside with another tube of the measurement on the OD. This way it will self align. Any better ideas, or a sure way to check my work. WITHOUT FARMING OUT!!!! Smart guy. Thanx in advance.

 

[mustang70]

I think the way the pro's do it is by putting a rod all the way through the rear end that is the same ID as the axle tubes. Then use the main caps to hold it in place. That will make sure everything is aligned correctly. That's how I plan on doing it when the time comes for me.

 

[D.Hearne]

Do what mustang70 says. A shaft all the way thru will guarantee a good alignment as long as the shaft is perfectly straight.The tube inside a tube may work, but the shaft idea will work.You also need to weld it into a jig to maintain the pinion angle.

 

[10secgoal]

Do what mustang70 says. A shaft all the way thru will guarantee a good alignment as long as the shaft is perfectly straight.The tube inside a tube may work, but the shaft idea will work.You also need to weld it into a jig to maintain the pinion angle.

How would I get the shaft to stay though ? Can one of you explain in a little more detail?
I need to more the perches anyway. I plan to bolt the rearend in and weld the perches once the pinion angle is right while in the car. Is that what you meant ? A jig if I planned to keep the perches ? Thanx again

 

[D.Hearne]

I can't say as to how to keep the shaft in place, I've never done a rearend, and don't know what resources you have available to do the job. I may do one myself one day if the need arises , I have a pretty complete welding shop to do it in.The only rear I've had narrowed was an 8.8 for my V8 Ranger, I had someone else do it ( didn't have the time then) As for your idea on the perches, that sounds like it'll work.

 

[mustang70]

What is the size difference between the caps that hold the diff bearings and the axle tubes? If there's a big difference then maybe put a short piece of tubing in the caps that can be tightened down and held in that way. Make sure the rod fits inside that tube pretty snug and slide it through after you put the center section into the housing.

 

[67coupe351w]

I think a sleeve like you were refering to would be the way I would do it. As you said it will self align everything and will also give you some extra beef to weld into.

Im sure this is what your thinking but I would cut a section out of each side some where at the halfway point from centersection to the end and then reweld the end and chunk of tube on.

We built a custom rear end for the off road vehicle that was my senior deisgn project. We used sleeves to make sure everything stayed alined durring welding and just did it with the rear end laying on a table.

 

[TurboDoctor]

Odds are even once you mock up the fit and burn all your welds, the tubes will still be tweaked and have to be pressed straight. It is very hard to keep the axles tubes from warping.

 

[67bluestang]

I've narrowed a few 9"ers. I had some aluminum "donuts" made where i worked that would fit the carrier bearing and housing ends. I then bought a 5' piece of 1.5" cold rolled steel. I used a tubing cutter (rented) to cut the axle tubes. It's more work than a cutoff saw, but the cutter leaves a beveled edge thats good for welding. I made some stands and tack welded them to my bench, set the rear end on them, leveled it, welded my 4 link brackets on, then installed the center section (without anything other than the donuts), ran the bar through it, slid the new housing ends on, squared them up and welded them up. I kept rotating the bar to make sure there was no binding during the welding.
If you plan on welding any brackets on the rear end, do them prior to welding the new ends on.

 

[HistoricMustang]

Figure all your stuff out and then talk to Currie Enterprises. Do not forget about the axles.

They did mine and performance has been great from Day 1.

HistoricMustang
www.historicmustang.com

 

[Mustang67Coupe]

How much is it costing now days to get a 9" shortened and the axles resplined? im gonna run into this fairly soon aswell

 

[HistoricMustang]

Currie shortened mine and made new axles and with freight to and from Georgia it was about $450. If your axles are tapered on the end, they can not be resplined.

Plus you get the "cool" emblem on the axle.

HistoricMustang
www.historicmustang.com

 

[1320stang]

67bluestang has it right. This is how my chassis builder buddy does his rearends. I've seen housing ends cut off, set up in the jig without even narrowing the housing, and the ends be 1/4"-3/8" out of alignment due to a warped housing. I think my buddy gets $150 to cut, narrow, and reweld the existing housing ends back on to your required width. Brackets, spring mounts, new billet ends, etc. are extra.

 

[ratio411]

I would farm this out personally...
The pros use a very meticulously built jig to get the rear fabbed up straight.
If you don't do it just so, you will be risking the whole job and any aftermarket parts you put in the thing now or later. You will wonder why your rear needs rebuilt so often.
If you do attempt this yourself, I know one thing for sure... the only part of the tubes that you add/subtract length from are the very ends. They cut off the outer bearing part and adjust the tube, then weld the outside back on. Cut/weld/adjust any other part of the tube and you are skrewd.
Dave